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SCD5028-2 Rev G 5/7/2014

Aeroflex Plainview

APPLICATION NOTE 1

USING INL ERROR CORRECTION FACTORS TO IMPROVE ACCURACY:

The information provided in this section is to address the constant Integral Nonlinearity (INL) that exists at

each angle of the RDC5028 Resolver to Digital Converter (RDC). This error is repeatable from chip to chip

and provides a look up Table of offsets that can be added to the output of the Resolver to Digital Converter

to obtain the 5.3 minute accuracy.

correction factor (in Minutes) that must be added to zero out the INL error.

A simple calculation can be performed to derive a correction factor for angles that fall between the angles

listed in Table II herein.

AL = Larger Angle

AS = Smaller Angle

CL = Correction Factor associated with larger Angle

CS = Correction Factor associated with smaller Angle

NA = New Angle

NCF = New Correction Factor

Formula:

NCF = CS + (((NA - AS) / (AL - AS)) * (CL - CS))

Example:

NCF = 5.10687 + (((15 – 14) / (16 – 14)) * (5.61783 - 5.10687))

NCF = 5.10687 + (((1) / (2)) * .51096)

NCF = 5.10687 + (.5 * .51096)

NCF = 5.10687 + .25548

NCF = 5.36235 minutes